\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage{german}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{graphicx}
\usepackage{xcolor}
\usepackage{algorithm}
\usepackage{algorithmic}
\setlength{\parindent}{0cm}
\setlength{\parindent}{0cm}
\author{}

\renewcommand \thesection{\Roman{section}}
\providecommand{\OO}[1]{\operatorname{O}\left(#1\right)}

\newtheorem{theorem_int}{Satz}[section]
\newtheorem{lemma}[theorem_int]{Lemma}
\newtheorem{proposition}[theorem_int]{Proposition}
\newtheorem{corollary}[theorem_int]{Korollar}

\newenvironment{proof}[1][Beweis] {
	\begin{trivlist}
		\item[\hskip \labelsep {\bfseries #1}]}
	{\end{trivlist}}
	
\newenvironment{example}[1][Beispiel]{\begin{trivlist}\item[\hskip \labelsep {\bfseries #1}]}{\end{trivlist}}
\newenvironment{remark}[1][Bemerkung]{\begin{trivlist}\item[\hskip \labelsep {\bfseries #1}]}{\end{trivlist}}

\newsavebox{\defbox} 
\newsavebox{\theobox} 

\newenvironment{definition}[1][Definition] { 
 \begin{lrbox}{\defbox} 
  \begin{minipage}{1\linewidth}\begin{trivlist}\item[\hskip \labelsep {\bfseries #1}]} 
 {\end{trivlist}\end{minipage}\end{lrbox} 
  \par\vspace{18pt}\noindent 
  \fbox{\usebox{\defbox}}\par} 

\newenvironment{theorem}[1] { 
 \begin{lrbox}{\theobox} 
  \begin{minipage}{1\linewidth}\begin{theorem_int} #1} 
 {\end{theorem_int}\end{minipage}\end{lrbox} 
  \par\vspace{18pt}\noindent 
  \fbox{\usebox{\theobox}}\par} 

\newcommand{\qed}{\nobreak \ifvmode \relax \else
      \ifdim\lastskip<1.5em \hskip-\lastskip
      \hskip1.5em plus0em minus0.5em \fi \nobreak
      \vrule height0.75em width0.5em depth0.25em\fi}



\title{
	Numerik
}

\begin{document}
  \maketitle
 
  \tableofcontents
  
  \newpage
  \input{quad}
  \newpage
  \input{eigen}
  \newpage
  \input{lineqn}
  \newpage
  \input{dgl}
  
\end{document}